Breaking EQ 7.4 Riecter.....about 20 min ago...New Zealand....Tsunami alert

[opihimoimoi]

no details....

[lapfog_1]

1. USGS has it at 7.8

100 miles west of Invercargill on the south island.

http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/at00764975.php

[opihimoimoi]

4. My Bad.....I hope all is well....

[lapfog_1]

7. Local news in NZ is reporting it at 6.8 to 7.0

so maybe USGS is off this time.

[armyowalgreens]

10. The initial 7.8 measurement has been confirmed by the USGS...

[ColbertWatcher]

6. SEVEN POINT EIGHT!? Damn! n/t

[lapfog_1]

9. USGS is now confirming 7.8

no longer reported as "preliminary".

Fortunately, this one was 21 miles deep (epicenter).

no tsunami so far.

[ColbertWatcher]

24. "21 miles deep" Good. n/t

[armyowalgreens]

2. Doesn't a warning mean that it is imminent?

[lapfog_1]

11. no, it simply means that a large earthquake has struck somewhere

in the ocean. We don't have enough tsunami monitoring stations to either announce one or preclude one.

Remember that a tsunami that far out in the ocean might generate a wave only a few inches high that, when it hits the continental shelf, becomes a killer.

[armyowalgreens]

3. According to my calculations, a potential Tsunami will hit the coast 20 to 40 minutes after...

The earthquake. That would be according to the closest shore of New Zealand.

For now, we wait.

[lapfog_1]

5. The quake is already 1 hour old...

but news of a tsunami might take a while.

trying to find a live TV coverage, but nothing so far.

[armyowalgreens]

8. It could be a lapse in the news feed. But I doubt it.

Even with a 20 minute delay, we would have heard by now. But maybe give it another 30 minutes to an hour. Who knows.

[lapfog_1]

15. Here is the Pacific Tsunami warning with their calculated times

THIS BULLETIN IS ISSUED AS ADVICE TO GOVERNMENT AGENCIES. ONLY
NATIONAL AND LOCAL GOVERNMENT AGENCIES HAVE THE AUTHORITY TO MAKE
DECISIONS REGARDING THE OFFICIAL STATE OF ALERT IN THEIR AREA AND
ANY ACTIONS TO BE TAKEN IN RESPONSE.

AN EARTHQUAKE HAS OCCURRED WITH THESE PRELIMINARY PARAMETERS

ORIGIN TIME - 0923Z 15 JUL 2009
COORDINATES - 46.1 SOUTH 166.3 EAST
DEPTH - SHALLOWER THAN 100 KM
LOCATION - OFF W. COAST OF S. ISLAND N.Z.
MAGNITUDE - 7.8

EVALUATION

IT IS NOT KNOWN THAT A TSUNAMI WAS GENERATED. THIS WARNING IS
BASED ONLY ON THE EARTHQUAKE EVALUATION. AN EARTHQUAKE OF THIS
SIZE HAS THE POTENTIAL TO GENERATE A DESTRUCTIVE TSUNAMI THAT CAN
STRIKE COASTLINES IN THE REGION NEAR THE EPICENTER WITHIN MINUTES
TO HOURS. AUTHORITIES IN THE REGION SHOULD TAKE APPROPRIATE
ACTION IN RESPONSE TO THIS POSSIBILITY. THIS CENTER WILL MONITOR
SEA LEVEL GAUGES NEAREST THE REGION AND REPORT IF ANY TSUNAMI
WAVE ACTIVITY IS OBSERVED. THE WARNING WILL NOT EXPAND TO OTHER
AREAS OF THE PACIFIC UNLESS ADDITIONAL DATA ARE RECEIVED TO
WARRANT SUCH AN EXPANSION.

ESTIMATED INITIAL TSUNAMI WAVE ARRIVAL TIMES AT FORECAST POINTS
WITHIN THE WARNING AND WATCH AREAS ARE GIVEN BELOW. ACTUAL
ARRIVAL TIMES MAY DIFFER AND THE INITIAL WAVE MAY NOT BE THE
LARGEST. A TSUNAMI IS A SERIES OF WAVES AND THE TIME BETWEEN
SUCCESSIVE WAVES CAN BE FIVE MINUTES TO ONE HOUR.

LOCATION FORECAST POINT COORDINATES ARRIVAL TIME
-------------------------------- ------------ ------------
NEW ZEALAND MILFORD SOUND 44.6S 167.9E 0951Z 15 JUL
BLUFF 46.6S 168.3E 1031Z 15 JUL
WESTPORT 41.8S 171.6E 1116Z 15 JUL
DUNEDIN 45.9S 170.5E 1157Z 15 JUL
AUCKLAND(W) 37.1S 174.2E 1217Z 15 JUL
NEW PLYMOUTH 39.1S 174.1E 1233Z 15 JUL
NELSON 41.3S 173.3E 1241Z 15 JUL
WELLINGTON 41.3S 174.8E 1329Z 15 JUL
LYTTELTON 43.6S 172.7E 1345Z 15 JUL
NAPIER 39.5S 176.9E 1427Z 15 JUL

BULLETINS WILL BE ISSUED HOURLY OR SOONER IF CONDITIONS WARRANT.
THE TSUNAMI WARNING WILL REMAIN IN EFFECT UNTIL FURTHER NOTICE.


I note that it's only 10:35 UTC right now... so Bluff and Milford Sound should have been hit if they are going to be hit.

[ProfessorGAC]

16. Depth Less Than 100km?

Every spot of water on the earth less than 100 km deep! There has to be error in there somewhere. Perhaps it meant less than 100 meters, which would be pretty shallow for the ocean. But, that is just a guess. I wonder if they've noticed this mistake.
GAC

[lapfog_1]

17. epicenter of the quake is usually deep in the mantle of the earth

this one was about 20 miles deep. Fairly deep as these things go, but not atypical.

The real question is... at the bottom of the ocean, in the vicinity of this quake, did the ocean bottom shake side to side or did it drop (or rise) at the fault line.

If it drops or rises at the fault line, that CAN (but not always) produce a tsunami. If it simply shakes side to side (or slips in some direction on the plane of the ocean bottom), pretty much no tsunami.

[ProfessorGAC]

20. Now I Get It

I interpreted it wrongly. I thought they were talking about the depth of the water at quake center. My fault. When the tsunami discussion started, i immediately started thinking water!

Your explanation makes perfect sense.
GAC

[Dennis Donovan]

12. The earthquake was centered approx 100mi off of the NZ coast...

A tsunami would hit the coast in a matter of minutes.

[armyowalgreens]

14. Yeah I just realized I doubled instead of halved. It would be about 10-20 minutes.

The average speed is 500-1000 km/hr. The distance is 100 miles.

[demoleft]

13. magnitudo 7.8 on the richter scale.

33 km in earth depth.

"An earthquake of this size has the potential to generate a destructive tsunami that can strike coastlines in the region near the epicentre within minutes to hours," the warning centre said in a statement.

The quake was detected at 0922GMT (2122 local time), reports said.

bbc, http://news.bbc.co.uk/2/hi/asia-pacific/8151530.stm


damn, hopefully no tragedy.

[Hubert Flottz]

18. Take Care!

I'm wishing you good luck.

[malaise]

19. Damn!

Here's a good link

http://www.radionz.co.nz/

[Clear Blue Sky]

21. Hobbits heading for the hills...

[malaise]

23. Tsunami warning for Australia

http://www.illawarramercury.com.au/news/local/news/general/tsunami-warning-for-port-kembla-batemans-bay/1569071.aspx
<snip>

The Bureau of Meteorology (BOM) has issued a tsunami warning for large parts of the east coast of Australia.

The tsunami effects are expected at the following locations in NSW from these times:

# Port Kembla after 09:45 pm (EST) Wednesday

# Batemans Bay after 09:45 pm (EST) Wednesday

# Eden after 09:45 pm (EST) Wednesday

# Sydney after 10pm (EST) Wednesday

# Newcastle after 10.15pm (EST) Wednesday

The BOM warned of the possibility of dangerous waves, strong ocean currents and the possibility of some localised overflow onto the immediate foreshore.

The State Emergency Service issued this advice while the tsunami warning remains in place:

# While major evacuations in these areas are not required, people are advised to get out of the water and move away from the immediate water's edge of harbours, coastal estuaries, rock platforms and beaches.

# Boats in harbours, estuaries or shallow coastal water should return to

shore. Secure your boat and move away from the waterfront.

# Vessels already at sea should stay offshore in deep water until further

advised.

# Do not go to the coast to watch the tsunami, as there is the possibility of

dangerous, localised flooding of the immediate foreshore.

# Check that your neighbours have received this advice.

[Phoonzang]

22. It caused a 6 inch tsunami. No worries. nt